scholarly journals Machine learning prediction of UV–Vis spectra features of organic compounds related to photoreactive potential

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rafael Mamede ◽  
Florbela Pereira ◽  
João Aires-de-Sousa

AbstractMachine learning (ML) algorithms were explored for the classification of the UV–Vis absorption spectrum of organic molecules based on molecular descriptors and fingerprints generated from 2D chemical structures. Training and test data (~ 75 k molecules and associated UV–Vis data) were assembled from a database with lists of experimental absorption maxima. They were labeled with positive class (related to photoreactive potential) if an absorption maximum is reported in the range between 290 and 700 nm (UV/Vis) with molar extinction coefficient (MEC) above 1000 Lmol−1 cm−1, and as negative if no such a peak is in the list. Random forests were selected among several algorithms. The models were validated with two external test sets comprising 998 organic molecules, obtaining a global accuracy up to 0.89, sensitivity of 0.90 and specificity of 0.88. The ML output (UV–Vis spectrum class) was explored as a predictor of the 3T3 NRU phototoxicity in vitro assay for a set of 43 molecules. Comparable results were observed with the classification directly based on experimental UV–Vis data in the same format.

2020 ◽  
Vol 15 (9) ◽  
pp. 1934578X2095275
Author(s):  
Pham Hai Yen ◽  
Nguyen Thi Cuc ◽  
Phan Thi Thanh Huong ◽  
Nguyen Xuan Nhiem ◽  
Nguyen Thi Hoai ◽  
...  

From the leaves of Aralia chinensis, 3 oleanane-type triterpene glycosides have been isolated, including 1 new glycoside, 3β,23 -dihydroxyolean-12-ene-28-oic acid 3 -O-β-d-glucopyranosyl-(1→3)- α-l-arabinopyranosyl-(1→3)-β-d-glucuronopyranoside 28 -O-β-d-glucopyranosyl ester (named as araliachinoside A, 1), and 2 known ones, 3β,23 -dihydroxyolean-12-ene-28-oic acid 3 -O-α-l-arabinopyranosyl-(1→3)- β-d-glucuronopyranoside 28 -O-β-d-glucopyronosyl ester (2) and 3β-hydroxyolean-12-ene-28-oic acid 3 -O-β-d-glucurono pyranoside 28 -O-β-d-glucopyronosyl ester (3). Their chemical structures were elucidated by using a combination of high-resolution electrospray ionization-mass spectrometry, 1-dimensional and 2-dimensional nuclear magnetic resonance spectral data, and by comparison with previous literature. Compounds 1-3 displayed cytotoxic activity toward KB and HepG2 cell lines with half-maximal inhibitory concentration values ranging from 8.1 ± 0.1 to 15.7 ± 0.3 µM in in vitro assay.


2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Bamidele Joseph Okoli ◽  
Johannes Sekomeng Modise

The tolerance of Acacia decurrens, an invasive species, was exploited pharmacologically in this study. Phytochemical screening revealed important secondary metabolites. Importantly, the assay shows that ethyl acetate and methanol fractions are sources of phytochemicals compared to the hexane and chloroform fractions. A bioassay-guided in vitro assay of the extracts led to the eventual isolation of four bioactive compounds by column chromatography, identification, and characterisation with the aid of GCMS, UV-Vis, FTIR, and NMR. The antimicrobial screening by disc diffusion assay revealed 22.2%, 44.4%, 66.7%, and 77.8% microbial inhibition by 2-methyl-octahydro-indene-4-carboxylic acid (AD1), 6-methyldecahydro-1H-phenanthren-9-one (AD2), 8-hydroxytetradecahydro-chrysene-1-carb aldehyde (AD3), and 8,9-dihydroxy-7-(2-hydroxy-ethyl)-9,9a-hexahydro-1H,3H-2-thia-5a-aza cyclopenta[b]anthracen-6-one (AD4), respectively. Compounds AD3 and AD4 are the most potent antibacterial compounds against Gram-positive bacteria with MIC 12.5–6.25 μg/ml. Antioxidant study of the compounds assayed with DPPH and ABTS•+ revealed that compound (AD4) is the most efficient DPPH radical scavenger with IC50 30.07 ± 0.31 and ABTS•+ scavenging activity of 4363.2 ± 452.4 μmol of TE/gDW. This provides scientific information on four pharmacophores with phyto-antioxidants and antimicrobial potential, despite the classification of A. decurrens as a Category 2 invasive plant by the National Water Act.


2020 ◽  
Vol 58 (5) ◽  
pp. 533
Author(s):  
Nguyen Phi-Hung

From the whole plant of Isodon ternifolius collected in Vietnam, four triterpens including ursaldehyde (1), ursolic acid (2), b-sitosterol (3) and b-sitosteryl ferulate (4) were purified. Their chemical structures were determined by interpretation of NMR and MS data and comparison with the literatures. Compounds 1-4 were evaluated for their inhibitory activity against PTP1B enzyme activity using in vitro assay. Compounds 1 and 2 displayed potential activities with IC50 values of 16.92 ± 0.12 and 3.42 ± 0.45 μM, respectively. This is the first time that compounds 1 and 4 have been isolated from the Isodon genus and I. ternifolius has been evaluated for the PTP1B inhibitory activity.


Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 42
Author(s):  
Katrin Kuck ◽  
Guido Jürgenliemk ◽  
Bartosz Lipowicz ◽  
Jörg Heilmann

By using various chromatographic steps (silica flash, CPC, preparative HPLC), 16 sesquiterpenes could be isolated from an ethanolic extract of myrrh resin. Their chemical structures were elucidated by 1D and 2D NMR spectroscopy and HRESIMS. Among them, six previously unknown compounds (1–6) and another four metabolites previously not described for the genus Commiphora (7, 10, 12, 13) could be identified. Sesquiterpenes 1 and 2 are novel 9,10-seco-eudesmanes and exhibited an unprecedented sesquiterpene carbon skeleton, which is described here for the first time. New compound 3 is an 9,10 seco-guaian and the only peroxide isolated from myrrh so far. Compounds 1, 2, 4, 7–9, 11, 13–16 were tested in an ICAM-1 in vitro assay. Compound 7, as well as the reference compound furanoeudesma-1,3-diene, acted as moderate inhibitors of this adhesion molecule ICAM-1 (IC50: 44.8 and 46.3 μM, respectively). These results give new hints on the activity of sesquiterpenes with regard to ICAM-1 inhibition and possible modes of action of myrrh in anti-inflammatory processes.


2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Kwang Jin Lee ◽  
Na-Young Song ◽  
You Chang Oh ◽  
Won-Kyung Cho ◽  
Jin Yeul Ma

TheAcer tegmentosum(3 kg) was extracted using hot water, and the freeze-dried extract powder was partitioned successively using dichloromethane (DCM), ethyl acetate (EA), butyl alcohol (n-BuOH), and water. From the EA extract fraction (1.24 g), five phenolic compounds were isolated by the silica gel, octadecyl silica gel, and Sephadex LH-20 column chromatography. Based on spectroscopic methods such as1H-NMR,13C-NMR, and LC/MS the chemical structures of the compounds were confirmed as feniculin (1), avicularin (2), (+)-catechin (3), (−)-epicatechin (4), and 6′-O-galloyl salidroside (5). Moreover, a rapid on-line screening HPLC-ABTS+system for individual bioactivity of the EA-soluble fraction (five phenolic compounds) was developed. The results indicated that compounds1and2were first isolated from theA. tegmentosum. The anti-inflammatory activities and on-line screening HPLC-ABTS+assay method of these compounds in LPS-stimulated murine macrophages were rapid and efficient for the investigation of bioactivity ofA. tegmentosum.


IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 168053-168060 ◽  
Author(s):  
Pouya Soltani Zarrin ◽  
Niels Roeckendorf ◽  
Christian Wenger

2021 ◽  
Vol 16 (7) ◽  
pp. 1934578X2110336
Author(s):  
Nguyen T. Hong Chuong ◽  
Do T. Thuy Van ◽  
Giang T. Kim Lien ◽  
Pham H. Yen ◽  
Dan T. Thuy Hang ◽  
...  

The 2 new oleanane-type triterpene glycosides, 23-hydroxyoleanolic acid-[28- O- β-D-glucopyranosyl]-3- O-{ β-D-glucopyranosyl-(1→2)-[ β-D-glucopyranosyl-(1→3)]- β-D-galactopyranoside}, (1) and oleanolic acid-[28- O- β-D-glucopyranosyl]-3- O-{ β-D-glucopyranosyl-(1→2)-[ β-D-glucopyranosyl-(1→3)]- β-D-galactopyranoside} (2) were isolated from the roots of Aralia armata. Their chemical structures were elucidated by using a combination of high resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1 dimensional (1D), and 2 dimensional (2D) nuclear magnetic resonance spectral data, as well as by comparison with the previous literature. Compounds 1 and 2 displayed weak cytotoxic activity toward KB and HepG2 cell lines with IC50 values of 25.1 ± 1.2 and 23.7 ± 0.9 µM (for 1) and 29.5 ± 1.3 and 23.9 ± 0.7 µM (for 2), respectively, compared to that of the positive control compound, ellipticine (IC50: 1.3 ± 0.1 and 1.6 ± 0.1 µM, respectively) in in vitro assay.


Agriculture ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 436 ◽  
Author(s):  
Mohsen Niazian ◽  
Gniewko Niedbała

Classical univariate and multivariate statistics are the most common methods used for data analysis in plant breeding and biotechnology studies. Evaluation of genetic diversity, classification of plant genotypes, analysis of yield components, yield stability analysis, assessment of biotic and abiotic stresses, prediction of parental combinations in hybrid breeding programs, and analysis of in vitro-based biotechnological experiments are mainly performed by classical statistical methods. Despite successful applications, these classical statistical methods have low efficiency in analyzing data obtained from plant studies, as the genotype, environment, and their interaction (G × E) result in nondeterministic and nonlinear nature of plant characteristics. Large-scale data flow, including phenomics, metabolomics, genomics, and big data, must be analyzed for efficient interpretation of results affected by G × E. Nonlinear nonparametric machine learning techniques are more efficient than classical statistical models in handling large amounts of complex and nondeterministic information with “multiple-independent variables versus multiple-dependent variables” nature. Neural networks, partial least square regression, random forest, and support vector machines are some of the most fascinating machine learning models that have been widely applied to analyze nonlinear and complex data in both classical plant breeding and in vitro-based biotechnological studies. High interpretive power of machine learning algorithms has made them popular in the analysis of plant complex multifactorial characteristics. The classification of different plant genotypes with morphological and molecular markers, modeling and predicting important quantitative characteristics of plants, the interpretation of complex and nonlinear relationships of plant characteristics, and predicting and optimizing of in vitro breeding methods are the examples of applications of machine learning in conventional plant breeding and in vitro-based biotechnological studies. Precision agriculture is possible through accurate measurement of plant characteristics using imaging techniques and then efficient analysis of reliable extracted data using machine learning algorithms. Perfect interpretation of high-throughput phenotyping data is applicable through coupled machine learning-image processing. Some applied and potentially applicable capabilities of machine learning techniques in conventional and in vitro-based plant breeding studies have been discussed in this overview. Discussions are of great value for future studies and could inspire researchers to apply machine learning in new layers of plant breeding.


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